| 摘要 |
The instrument (10) e.g. endodontical file, has an end section (11) arranged for being mounted in a mandrel driven by an electric motor. A central zone (13) extends a proximal zone arranged adjacent to the end section. A distal zone extends the central zone and is arranged for assuring the guidance of the instrument in the canal. A cover of the distal, central and proximal zones presents a shape of inverted cone. The cover in the shape of inverted cone includes a part of large cross section corresponding to the distal zone and another part of small cross section corresponding to proximal zone. |
